The Fleming diode and De Forest Audion

The next major event was the discovery that an electrode operating at a positive voltage inside the evacuated envelope of a heated filament lamp would carry a current. The American inventor Thomas A. Edison had noted that the bulb of such a lamp blackened near the positive electrode, but it was Sir John Ambrose Fleming, professor of electrical engineering at Imperial College, London, who explored the phenomenon and in 1904 discovered the one-directional current effect between a positively biased electrode, which he called the anode, and the heated filament; the electrons flowed from ... (100 of 5,909 words)